/*========================== begin_copyright_notice ============================

Copyright (C) 2017-2021 Intel Corporation

SPDX-License-Identifier: MIT

============================= end_copyright_notice ===========================*/

#pragma once

#include "Compiler/MetaDataUtilsWrapper.h"

#include "common/LLVMWarningsPush.hpp"
#include <llvm/Pass.h>
#include <llvm/IR/Operator.h>
#include "common/LLVMWarningsPop.hpp"

namespace IGC {
/// @brief  This pass sets llvm fast math flags to relevant instructions, according
///         to the present compiler options.
///         -no-signed-zeros and -unsafe-math-optimizations sets nsz flag
///         -finite-math-only sets nnan and ninf flags
///         -fast-relaxed-math sets fast flag which implies all others (including arcp)
class SetFastMathFlags : public llvm::ModulePass {
public:
  /// @brief  Pass identification.
  static char ID;

  SetFastMathFlags();

  SetFastMathFlags(llvm::FastMathFlags Mask);

  SetFastMathFlags(llvm::FastMathFlags Mask, bool skipUnsafeFpMathAttr);

  ~SetFastMathFlags() {}

  virtual llvm::StringRef getPassName() const override { return "SetFastMathFlags"; }

  virtual bool runOnModule(llvm::Module &M) override;

  virtual void getAnalysisUsage(llvm::AnalysisUsage &AU) const override {
    AU.setPreservesCFG();
    AU.addRequired<MetaDataUtilsWrapper>();
  }

private:
  /// @brief  sets the given flags to all instruction supporting fast math flags in the given module.
  /// @param  F - the function
  /// @param  fmfs - the fast math flags
  /// @return true if made any changes to the module.
  static bool setFlags(llvm::Function &F, llvm::FastMathFlags fmfs);

  llvm::FastMathFlags m_Mask;

  // We need to distinguish between when the compiler uses the FastRelaxedMath flag alone
  // and when uses the FastRelaxedMath flag with unsafe-fp-math attribute.
  // For the option one, we set the new bool variable to true (we skip unsafe-fp-math attribute)
  bool m_skipUnsafeFpMathAttr = false;
};

} // namespace IGC
